1. Technical Field
The present disclosure relates to a light source device equipped with a high-output light source device constituted by a semiconductor laser device, and more particularly relates to a semiconductor laser light source device equipped with a heat dissipation member (heat sink) on the face where the semiconductor laser light is emitted, wherein the effect of cooling air on the light can be prevented while heat can be dissipated efficiently, and the accumulation of dust on optical parts can be suppressed.
2. Related Art
A conventional projector makes use of a discharge-type lamp, such as a high-pressure mercury vapor lamp or a xenon lamp, but configurations in which a light emitting diode or a semiconductor laser serves as the light source have been proposed because of their superiority in terms of power consumption and environmental burden (for example, JP2012-88451A, JP4711154B, JP2011-76781A, JP2012-63488A, JP2004-341105A, etc.).
In particular, hybrid light source that combine a semiconductor laser device with a phosphor are very promising as new lamp for high-brightness projectors that afford good safety.
In JP4711154B, for example, a projector is disclosed which is constituted by a blue semiconductor laser device and a wheel that includes a phosphor region that absorbs blue light and emits green light, a phosphor region that absorbs blue light and emits red light, and a transparent region with a light diffusing effect. While this wheel is rotated, blue light from the blue semiconductor laser device is converged on the wheel by a lens, and illumination light which is composed of the transmitted blue light and the green light and red light emitted from the phosphors is created.
JP2004-341105A discusses a blue-violet-light excited phosphor wheel coated with a phosphor that emits blue light, a phosphor that emits green light, and a phosphor that emits red light.
To achieve brighter illumination, a high-output excitation light source is necessary, and a structure has been studied in which a plurality of semiconductor laser devices are disposed in the same plane as described in JP2011-76781A. With a structure in which semiconductor laser devices are thus disposed in the same plane, when size is taken into account, the spacing between the semiconductor laser devices must be reduced. This tends to result in the accumulation of the heat from the semiconductor laser devices, which leads to lower light output and a shorter service life. In view of this, a method has been used in which the semiconductor laser devices are brought into contact with a heat dissipation member (heat sink), and the heat is dissipated by a cooling fan.
In a method involving the use of a cooling fan, it is good to provide the heat dissipation member on a plurality of faces in order to dissipate the heat more efficiently. For example, as shown in FIGS. 12A and 12B, a light source device in which heat dissipation members 50, 60 are formed on a side of the light emission face of a semiconductor laser device. However, when heat is dissipated by cooling fans 70a, 70b from a light source device such as this, the wind passes over the optical path, and there is the possibility that dust or the like will block the semiconductor laser light, which can lead to flicker.